Covering band for weft inserter driving mechanism in multiple-shed weaving machines

ABSTRACT

A covering band separating the weft inserters from their driving mechanism, for example, a driving chain in multiple-shed weaving machines wherein the band forcibly resiliently engages the inserters. The covering band possesses its highest elasticity in the direction of the driving force of the chain, and in the direction perpendicular to said driving force. In the directions lying intermediate, the direction of the driving force and the direction perpendicular thereto, the elasticity of the covering band is at its lowest. The covering band is firmly clamped along the two sides thereof on a guide for the chain.

Unite States Patent [1 1 Kramenic et al.

[ Jan. 28, 1975 COVERING BAND FOR WEFT INSERTER DRIVING MECHANISM IN MULTIPLE-SHED WEAVING MACHINES [75] Inventors: Zdenek Kramenic, Chocen; Zdenek Zabrodsky, Usti nad Orlici; Jana Didkova, Usti Nad Orlici;

Hradec Kralove, Usti nad Orlici; Rudolf lmramovsky, Usti nad Orlici, all of Czechoslovakia [73] Assignee: Vyzkummy Ustav Bavlnarsky, Usti nad Orlici, Czechoslovakia [22] Filed: June 11, 1973 [211 App]. No.: 368,604

[30] Foreign Application Priority Data June 12, 1972 Czechoslovakia 4062-72 [52] US. Cl. 139/12 [5 1] Int. Cl D03d 47/26 [58] Field of Search l39/ll,l2, 13,16,133,

[56] References Cited UNlTED STATES PATENTS 3.729.029 4/1973 Znhrodsky et al. l39/l2 Primary 1;'.\'aminw'-Henry S Jaudon {57] ABSTRACT A covering band separating the weft insertcrs from their driving mechanism, for example, a driving chain in multiple-shed weaving machines wherein the band forcibly resiliently engages the inserters. The covering band possesses its highest elasticity in the direction of the driving force of the chain, and in the direction perpendicular to said driving force. In the directions lying intermediate, the direction of the driving force and the direction perpendicular thereto, the elasticity of the covering band is at its lowest. The covering band is firmly clamped along the two sides thereof on a guide for the chain.

9 Claims, 5 Drawing Figures PATENTED 3,862,649

SHEET 10$ 2 COVERING BAND FOR WEFT INSERTER DRIVING MECHANISM IN MULTIPLE-SHED WEAVING MACHINES This invention relates to a covering band separating the weft inserters from their driving mechanism, for example, a chain in multiple-shed weaving machines.

The known multiple-shed weaving machines use for inserting weft into the shed either an upper drive or a so-called under-drive for the weft carriers.

Multiple-shed looms with an upper drive for the weft carriers produce the picking motion by a direct action of the beat-up dents against the weft carrier. The dents perform a reciprocating periodically repeated beat-up motion and apply pressure against the skewed rear portions of the weft carriers, thus pushing them ahead through the shed, in the direction of the weaving motion. However, the devices of this type are considerably susceptible to wear and particularly to deformations which may be the cause of serious troubles.

Another known embodiment utilizes the so-called under-drive for the weft carriers, and imparts the working motion to the weft carrier by applying pressure thereto by means of geared driving means. Their positive rotary motion does not serve for driving the carriers, but permits a continuous contact of the driving mechanism with the carriers. The warp threads of the lower sheet are pushed apart by the teeth warp theads they deposit themselves in groups onto the bottoms of the tooth spaces as they slip through beneath the carrier, and after passage of the carrier they again assume their initial arrangement. The device is more reliable in operation than those of the first upper drive type, however, there is a risk that the warp threads will be damaged because of their being nipped between the teeth.

Further, there has been proposed a construction for the underdrive of the weft inserters which employs the rolling principle. Smooth rollers disposed with proper spacings on a driving chain act across the warp threads on similar rollers which are built-in in the weft inserters. Under certain conditions, however, mainly at low speeds under which this embodiment is able to operate, a small increase of resistance during the passage of the weft inserters through the sheds results in warp thread breakages.

In order to eliminate the disadvantages in underdrives mentioned herein before, a covering band has been interposed between the lower warp sheet and the driving mechanism of the weft carrier. In a known device of this type, a rubber band has been used, the band being interposed between the moving driving mechanism and the weft carriers. However, the uniform elasticity of the rubber band brings about the undesirable condition of a gradually increased tension in the warp threads followed by a violent tension release, which has a detrimental effect on the warp threads.

The object of the invention is to remove the enumeratecl drawbacks and to provide a covering band of such construction that it permits dissipation of the force from the driving of the weft inserters and to transfer the components thereof to the sides for a firm clamping of the covering band, the band employed being elastic in the direction of movement of the inserters and also in the transverse direction.

The covering band of the invention possesses its highest elasticity in the direction of the driving force of the driving chain, acting across the covering band on the inserters, and in the direction perpendicular to said driving force, whereas in the directions lying intermediate the direction of the driving force and the direction perpendicular thereto the elasticity of the covering band is at its lowest, the covering band being logitudinaly firmly clamped at the two sides thereof, on a guide for the chain.

Another feature of the invention is that the covering band is formed of a fabric, the warp/weft system of which is oriented in such a way that the warp threads and the wefts form with the direction of the driving force of the chain an angle of substantially 45; further, it is advantageous that the warp weft system is a twill weave.

The covering band is preferably held with each of the two longitudinal borders thereof clamped by means of a splice plate on a rail which is removably fastened in a cut provided in the guide for the chain; the rail may be removably held in the cut in the guide by means of bayonet closures formed by a slot provided in the rail and a pin fixed in the guide within the cut and extending into said slot.

From the viewpoint of easy assembly and also otherwise advantageous properties, the covering band may be formed of a hose into which two bars are inserted, each of such bars being connected with the covering band, the thus formed assembly extending at each of the two longitudinal borders thereof, reinforced by one of the bars, into a corresponding oblique groove provided in the guide of the chain, the groove having hooked slots into which pins fixed in the guide extend, the pins forming disengageable bayonet closures with the said slots.

Another feature is that the connection of the bar with the covering band is effected by means of a thermoplastic material introduced into an opening in the bar and sealed thereto and to the covering band,

The running-on of the inserters onto the covering band is facilitated with a covering band made in such a way that a cut-out extends on the entry side of the inserter from the start of the covering band as far as the entry point of the inserters, the width of the cut-out decreasing in the direction toward said point.

Examples of embodiments of the invention are shown in the accompanying drawings in which:

FIG. I is a view in plan of an entry portion ofa covering band;

FIG. 2 is a fragmentary perspective view of a detail of a first means for clamping a covering band by means of spaced parallel rails and splice plates clamped thereto;

FIG. 3 is a fragmentary view in perspective of a detail of another clamping means for securing a covering band, the clamping means at one side of the covering band being shown, such clamping means employed and inserted by at each edge of the covering band;

FIG. 4 is a view in deviation of a portion of an inserted bar; and

FIG. 5 is a section through two inserted bars and a covering band at the point of their mutual connection.

Turning now to FIGS. 1 and 2, a covering band 1 is interposed between a driving mechanism of weft inserters, i.e. between a chain 2 and a weft inserter 3, the latter moving in the direction of the arrow. It is understood that instead ofa driving chain 2 there may be employed an endless belt or the like. The covering band I is made for example of a woven polyamide fabric,

preferably in twill weave; and it is oriented in such a way that the covering band 1 possesses its highest elasticity in the direction of travel of the endless chain 2 shown by the arrow in FIG. 2, acting across the covering band 1 on the inserters 3 and in the direction 11 perpendicular to the length of the covering band I force 10. In the direction 12, 13, which lie intermediate the directions and 11, the elasticity of the covering band 1 is at its lowest. This is achieved when the warp- /weft system of the covering band 1 is oriented in such a way that the warp threads and the wefts extend in the directions 12, 13, respectively, (FIG. 1), Le. the warp and weft threads form an angle of at least approximately 45 with the direction of force 10.

The covering band 1 is lengthwise firmly clamped, at the two sides thereof on the sides of a guide channel 21 of the chain 2, two sides of such channel being shown in FIG. 2 and one side of such channel being shown in FIG. 3.

In the embodiment according to FIG. 2, each of the two longitudinal borders 14, of the band is clamped on a respective rail 4 by means of a splice plate 41 and screws 42. The rail 4, 4 is advantageously removably fastened in a cut 210 provided in the guide 21 of the chain 2; such fastening is effected by means of a bayonet closure which is formed by a slot 43 provided in the rail 4 and a pin 211 fixed on the guide 21 within the cut 210 and extending into said slot 43. An identical fastening (not shown) is supplied for the guide 21'.

The covering band 1 is clamped between the rail 4 and the splice plate 41 by a plurality of screws 42. It is to be understood that the rail 4 includes a plurality of such bayonet closures arranged one after the other.

In the embodiment according to FIGS. 3 and 5, the covering band 1 is made of a hose in which two bars 50, 51 are inserted, each of which is connected with the covering band 1. The thus formed assembly extends along each ofits longitudinal borders, each border reinforced by a respective one of the bars 50, 51. Oblique grooves 212 (see FIG. 3.) are provided in the guide 21, 2l'for the chain 2. Slots 16 are provided both in the bars 50 51 and the respective portion of the covering band 1. Pins 211 which are fixed in the guide extend into the grooves 212, thus forming an easily disengageable bayonet closure.

The connection of the bars 50, 51 with the covering band 1 is effected by means of a thermoplastic material 17, introduced into an opening 52 provided in thebars 50 and 51 and fused thereto and to the covering band 1.

In order to prevent the covering band 1 from excessive wear due to the weft inserters 3 entering thereon, a cutout 191 (FIG. 1) extends from the end of the band entered by the inserters 3 and extending from such entering end 19 of the covering band 1 as far as the entry point 190 of the inserters 3 onto the covering band 1, the width of the cutout decreasing in the direction towards said point 190. I

For a longer life, the covering band is heat set; it is useful to treat the surface thereof by means of known chemical agents to insure the hand against felting and pilling and for reducing the coefficient of friction of the band.

The thus prepared covering band I is reliable in operation, has a long life and high strength. It does not cause a prohibitive increase of frictional resistnace between it and the inserter during the driving of the inserters nor does it cause jumps in the tension of the weft threads due to deformations of the band. It is easily removable, and it can as easily be fitted into the machine.

Although the invention is illustrated and described with reference to a plurality of preferred embodiments thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a plurality of preferred embodiments, but is capable of numerous modifications within the scope of the appended claims.

What is claimed is:

1. In a multiple-shed weaving machine having a plurality of travelling weft inserters, a flexible endless driving member for driving the weft inserters and a resilient covering band forcibly engaging the inserters and separating them from the driving member, the improvement which comprises: the covering band possesses its highest elasticity in the direction of the driving force of the driving member and in the direction perpendicular to said driving force, in the direction lying intermediate the direction of the driving force and the direction perpendicular thereto the elasticity of the covering band is at its lowest and means for firmly clamping the covering band along the two sides thereof on fixed structure of the machine.

2. Apparatus as claimed in claim 1 wherein the band is formed of a fabric the warp/weft system of which is oriented in such a way that the warp threads and the weft threads are disposed at an angle of substantially 45 with respect to the direction of the driving force of the driving member.

3. Apparatus as claimed in claim 2 wherein the warp- /weft system of the band is a twill weave.

4. Apparatus as claimed in claim 1 wherein each of the two longitudinal borders of the band is clamped on a guide rail for the driving member.

5. Apparatus as claimed in claim 1 wherein each of the two longitudinal borders of the band is clamped by means of a splice plate on a rail, the rail being removably fastened in a cut provided in a guide for the driving member.

6. Apparatus as claimed in claim 5 wherein the removable fastening of the rail in the cut of the guide is effected by means of bayonet closures formed by a slot provided in the rail and a pin fixed in the guide, within the cut, and extending into said slot.

7. Apparatus as claimed in claim 1 wherein the band is formed of a hose into which two bars are inserted, each of such bars being connected with the covering band the thus formed assembly extending along each of the two longitudinal borders thereof, reinforced by one of the bars into a corresponding oblique groove provided in a guide for the driving member, hooked slots in the guide into which there extend within the said oblique groove pins of fixed to the guide and forming a disengageable bayonet closure with the slots.

8. Apparatus as claimed in claim 6 wherein the connections of the bars with the covering band is effected by means of a thermoplastic material introduced into opening in the bars and sealed thereto and to the covering band.

9. Apparatus as claimed in claim 1 wherein the band on the end thereof entered by the inserter has a cut-out extending from the start of the covering band as far as the entry point of the inserters the width of such cutout decreasing in the direction from the start of the band towards said entry point of the inserters. 

1. In a multiple-shed weaving machine having a plurality of travelling weft inserTers, a flexible endless driving member for driving the weft inserters and a resilient covering band forcibly engaging the inserters and separating them from the driving member, the improvement which comprises: the covering band possesses its highest elasticity in the direction of the driving force of the driving member and in the direction perpendicular to said driving force, in the direction lying intermediate the direction of the driving force and the direction perpendicular thereto the elasticity of the covering band is at its lowest and means for firmly clamping the covering band along the two sides thereof on fixed structure of the machine.
 2. Apparatus as claimed in claim 1 wherein the band is formed of a fabric the warp/weft system of which is oriented in such a way that the warp threads and the weft threads are disposed at an angle of substantially 45* with respect to the direction of the driving force of the driving member.
 3. Apparatus as claimed in claim 2 wherein the warp/weft system of the band is a twill weave.
 4. Apparatus as claimed in claim 1 wherein each of the two longitudinal borders of the band is clamped on a guide rail for the driving member.
 5. Apparatus as claimed in claim 1 wherein each of the two longitudinal borders of the band is clamped by means of a splice plate on a rail, the rail being removably fastened in a cut provided in a guide for the driving member.
 6. Apparatus as claimed in claim 5 wherein the removable fastening of the rail in the cut of the guide is effected by means of bayonet closures formed by a slot provided in the rail and a pin fixed in the guide, within the cut, and extending into said slot.
 7. Apparatus as claimed in claim 1 wherein the band is formed of a hose into which two bars are inserted, each of such bars being connected with the covering band the thus formed assembly extending along each of the two longitudinal borders thereof, reinforced by one of the bars into a corresponding oblique groove provided in a guide for the driving member, hooked slots in the guide into which there extend within the said oblique groove pins of fixed to the guide and forming a disengageable bayonet closure with the slots.
 8. Apparatus as claimed in claim 6 wherein the connections of the bars with the covering band is effected by means of a thermoplastic material introduced into opening in the bars and sealed thereto and to the covering band.
 9. Apparatus as claimed in claim 1 wherein the band on the end thereof entered by the inserter has a cut-out extending from the start of the covering band as far as the entry point of the inserters the width of such cut-out decreasing in the direction from the start of the band towards said entry point of the inserters. 